It is the purpose of the research proposed here to contribute toward understanding the relationship and the potential of efforts to control the rising costs of care through institutional sharing arrangements, as they are undertaken by multi-hospital systems and by Health Systems Agencies. The problem which this research proposes to address is that of the inadequate and unorganized state of current knowledge available to Health Systems Agencies concerning the policy and planning relevance of multi-hospital systems for realizing cost containment through institutional sharing. Specific objectives proposed are: 1) to define the attributes, status, and parameters of sharing within a multi-hospital system, 2) to determine the extent to which multi-hospital system membership is a factor to be considered by HSAs in planning areal sharing arrangements, 3) to estimate the benefits derived from various sharing arrangements within a multi-hospital system, and 4) to investigate the ways in which presence of an institutional member of a multi-hospital system in an HSA's Health Service Area has policy and planning relevance for the HSA's cost containment goals. Methodologies to be employed include: 1) critical literature review and abstracting of an indexed inventory of propositions and empirical findings on institutional sharing, 2) compilation and analysis of existing survey, financial, operating, managerial, and governance data of one multi-hospital system for purposes of a detailed case description, and 3) a policy analysis and evaluation using existing regulatory and corporate sources.